fix: pass env variables to mcp server

langchain_mcp_client.py

@@ -1,3 +1,4 @@
+import os
 import os.path
 import json
 from typing import Tuple, Any
@@ -55,6 +56,8 @@ async def lc_mcp_exec(request: str, history=None) -> Tuple[str, list]:
         async with stdio_client(server_params) as (read, write):
             async with ClientSession(read, write) as session:
                 await session.initialize()
+                
+                # Load tools and create the agent
                 tools = await load_and_enrich_tools(session)
                 agent = create_react_agent(llm, tools)
 
@@ -103,13 +106,45 @@ def load_table_summary(path: str) -> str:
         return file.read()
 
 
+
 def get_server_params() -> StdioServerParameters:
+    load_dotenv()
+    
+    # Prepare the environment dictionary to pass to the subprocess
+    subprocess_env = {}
+
+    # List of environment variables that the postgre_mcp_server.py needs
+    required_vars_for_server = [
+        # "TABLE_SUMMARY_PATH",
+        "DB_URL",
+        "DB_SCHEMA",
+        "PANDAS_KEY",
+        "PANDAS_EXPORTS_PATH",
+        # "GEMINI_API_KEY",
+        # "GEMINI_MODEL",
+        # "GEMINI_MODEL_PROVIDER",
+        # "OPENAI_MODEL_PROVIDER",
+        # "OPENAI_MODEL",
+        # "OPENAI_API_KEY",
+    ]
+
+    for var_name in required_vars_for_server:
+        value = os.getenv(var_name) 
+        if value is not None:
+            subprocess_env[var_name] = value
+        else:
+            logger.warning(f"Environment variable {var_name} not found for passing to MCP server subprocess.")
+
+    logger.info(f"Passing environment to MCP server subprocess: {subprocess_env.keys()}")
+
     return StdioServerParameters(
         command="python",
-        args=[os.environ["MCP_SERVER_PATH"]],
+        args=[os.environ["MCP_SERVER_PATH"]], # MCP_SERVER_PATH itself must be available to this client
+        env=subprocess_env 
     )
 
 
+
 async def load_and_enrich_tools(session: ClientSession):
     tools = await load_mcp_tools(session)
     return tools

postgre_mcp_server.py

@@ -33,6 +33,9 @@ class DbContext:
     pool: asyncpg.Pool
     schema: str
 
+# Load environment variables
+load_dotenv()
+
 
 # Database connection lifecycle manager
 @asynccontextmanager